merge.applyupdates: add all actions returned from merge state

At the moment this is a no-op (the only actions defined are 'r', 'a' and 'g'),
but soon we're going to add other sorts of actions to the dictionary returned
from mergestate.actions().

mercurial/merge.py

@@ -1151,8 +1151,8 b' def applyupdates(repo, actions, wctx, mc'
     removed += msremoved
 
     extraactions = ms.actions()
-    for a in 'rag':
-        actions[a].extend(extraactions[a])
+    for k, acts in extraactions.iteritems():
+        actions[k].extend(acts)
 
     progress(_updating, None, total=numupdates, unit=_files)